Personally, I really do think medical licenses are too restrictive. I think a lot of very talented people who could have made great doctors end up pursuing other careers, because they weren't willing to commit to a pre-med undergrad + 4 years med school + residency while they were 18, which the typical age that people have to make that decision.

I also think the medical field suffers because the only people who become doctors were people who have been on the track for becoming a doctor their whole life. An engineering firm might have artists and philosophers and tradesmen who are passionate about engineering and self-taught, bringing very unique perspectives to various problems. These same people have enough talent, motivation and humility that they probably would make great doctors too.

And I know for a fact that doctors would benefit from e.g. a systems engineering or fluid dynamics background to better understand the medicines they're prescribing and be more equipped to prescribe the right one in the right doses, or maybe a math/statistics background to understand unintuitive numerical data such as "X diagnostic test is 99% accurate.... [fine print] because it reports 100% of cases as negative and only 1% of cases are ever positive".

My imagination can only go so far with examples, and I know there are very good reasons for the tight restrictions, but I strongly believe the restrictions are too tight.